Product Name:MF73T-1
Features:
1. Small size, large power, strong ability to suppress inrush current
2. The material constant (B value) is large, the residual resistance is small, and the power consumption is small
3. High current, long life, high reliability
4. Easy to install circuit board, full series, wide application range
Scope of application:
1. High-power switching power supply, conversion power supply, UPS power supply
2. High-power power battery charger, electric vehicle charger
3. High-power LED lamps, high-power electronic energy-saving lamps and other lighting fixtures
Thermistor MF73T1-20/6 MF73T-1-20/6
MF73T1-0.7/22
MF73T-1-4.7/20
MF73T-1-3/9
MF73T-1-15/13
MF73T-1-0.5/32
MF73T-1-18/11
Main technical parameters of NTC thermistor:
1. Zero power resistance value RT
At a specified temperature, the resistance value measured by measuring power that causes a change in resistance is negligible relative to the total measurement error.
2. Rated zero power resistance value R25
The design resistance value of the thermistor value usually refers to the zero power resistance value measured at 25°C and is marked on the thermistor.
3. B value
The B value is the thermal index of a negative temperature coefficient thermistor, which is defined as the ratio of the natural logarithm difference between the zero power resistance values at two temperatures to the difference between the reciprocals of these two temperatures. Namely:
Formula: RT1 - zero power resistance value at temperature T1
RT2 - Zero power resistance value at temperature T2
Unless otherwise noted, the B value is calculated from the zero power resistance values of 25°C (298.15K) and 50°C (323.15K), and the B-value is not a strict constant over the operating temperature range.
4. Zero power resistance temperature coefficient αT
It refers to the ratio of the rate of change of the zero power resistance value of a thermistor with temperature to its zero power resistance value at a specified temperature. Namely:
Formula: αT – temperature coefficient of zero power resistance at temperature T
RT – Zero power resistance value at temperature T
T – Temperature (expressed in K)
B- B value
5. Dissipation coefficient δ
At the specified ambient temperature, the ratio of the change in dissipated power of the thermistor to its corresponding temperature change, i.e.:
In the operating temperature range, the δ varies with the ambient temperature.
6. Thermal time constant τ
At zero power, when the temperature changes abruptly, the thermistor body temperature changes by 63.2% of the time required for the first and last temperature differences.
τ is proportional to the heat capacity C of the thermistor and inversely proportional to its dissipation coefficient δ. Namely:
7. Maximum steady-state current
The maximum continuous current allowed to be applied to the thermistor at an ambient temperature of 25°C.
8. Resistance-temperature characteristics
The dependence between the zero power resistance value of a thermistor and the temperature of its resistor.
//www.chip100.com/